The American Joint Committee has been engaged in a clinical research project to develop staging classifications for cancer of all anatomic sites. During the past year following considerable thought as to the future activities of the AJC, the following plan has resulted: 1) To complete classifications where further work is needed: bone, central nervous system, melanoma, and GU malignancies; (2) To encourage the use of classification for staging in end results reporting, reporting to journals, libraries, cancer registries, and medical societies; 3) To work with groups on a national level who are doing cancer staging, i.e., SEER, CCPDS, CICA, ACCC, ACOS, and other central and hospital registries, to develop a common computer code; (4) To further refine, publicize, distribute and encourage use of specific site cancer data collection forms; 5) To test the validity of the classifications, with data from SEER and other groups; 6) To evaluate biological markers and other factors which are important in classification of specific cancers and their prognoses, and to determine their relative importance; 7) To evaluate the relative importance and cost effectiveness of various tests and procedures utilized in pretreatment clinical staging and in posttreatment follow-up evaluations, in an effort to discourage over-utilization of expensive tests which are rarely positive and add little to management.